High-voltage diamond Schottky rectifiers

In this paper, we simulate and fabricate diamond Schottky rectifiers. The growth rate of pure diamond single crystal epitaxial is from 0.5 up to 100/spl mu/m/hr with boron doping concentration around 1/spl times/1014 cm/sup -3/ to 1/spl times/10/sup 16/ cm/sup -3/. A "liftoff" technology is used to provide the wafer. Theoretical calculation indicates that the diamond Schottky rectifier has a significant lower voltage drop than SiC Schottky rectifier and comparable with SiC PiN diode with the blocking voltage higher than 10 kV. A maximum 50 kHz operating frequency at switching voltage 25 kV is shown based on thermal limit. Vertical structure devices with 70/spl mu/m epi layer achieve 18 A/cm/sup 2/ at 250/spl deg/C at 7 V forward drop as shown with a breakdown voltage of only 600 V. A breakdown voltage of 8 kV at 100/spl mu/m distance is recorded for lateral structure devices without ohmic contact (back to back Schottky diodes), 12.4 kV at 300/spl mu/m distance.